Colin Kaepernick's turn as the 49ers' starting quarterback had been fairly smooth through two weeks -- he barely broke a sweat in a rout of Chicago, then bounced back from an early interception to pull away from Drew Brees and the Saints.

The young QB found the going a little rockier Sunday in St. Louis, mostly because of his own doing.

Now, after a 16-13 overtime loss to the Rams, 49ers coach Jim Harbaugh may have to spend a little more time weighing the Kaepernick-Alex Smith conundrum again.

"I'll let you know if there's a change, but right now, I think it'll be the same as it was this week," Harbaugh said following the game. "I'm proud of Kap, proud of the way he played. He handled himself well, gave our team a chance to win."

It would be tough for Harbaugh to go back to Smith, and he certainly does not want to play musical chairs at quarterback. The 49ers will need Kaepernick to keep his mistakes to a minimum, though -- something he did not do Sunday.

The 49ers held a 7-0 lead midway through the third quarter of a defensive struggle, when Kaepernick took a snap inside his own 10 and unadvisedly scrambled back into the end zone. He then attempted to throw a pass away for an imcompletion, but he failed to get the ball back to the line of scrimmage -- that drew a flag for intentional grounding and cost San Francisco a safety.

Kaepernick's team still had the lead in the closing moments of regulation, when he made his second huge error. Attempting to run a triple-option out of the pistol from deep in his own territory, Kaepernick launched a pitch over Ted Ginn's head. St. Louis' Janoris Jenkins recovered and rolled into the end zone for a touchdown; the Rams converted a two-pointer to tie the game.

Following his two costly mistakes, Kaepernick reminded everyone why he's starting right now: With the game knotted at 10, the athletic Kaepernick broke loose for a 50-yard run that set up a late field goal. That wasn't enough in the end -- the Rams sent the game to overtime with a long Greg Zuerlein field goal, then won it after San Francisco failed on a pair of OT possessions.

Kaepernick inherited the 49ers' QB job during a Week 10 battle with these same Rams. He helped spark San Francisco to 17 fourth-quarter points to erase a 17-7 deficit. That game ended in a 24-all tie.

Since that time, Kaepernick has been one of the stories of the NFL, his run-pass ability adding another dimension to an often stagnant San Francisco offense. The results spoke for themselves in his first two starts, with the 49ers looking more than dangerous enough to be considered a Super Bowl favorite.

Sunday's loss may not drastically change that, but it ought to give Harbaugh pause. If nothing else, with Seattle's dramatic win in Chicago, it increases the pressure on San Francisco to continue winning. Seattle now sits just 1.5 games back in the NFC West (that tie skewing the standings a bit), with the two teams set for a Week 16 matchup in Seattle.

How will Kaepernick respond to his first big piece of adversity? That's the question facing Harbaugh over the coming week.